Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Donn Young, a biostatistician at Ohio State University’s Comprehensive Cancer Center who studied more than 300,000 cancer patients, said the supposed phenomenon is mostly based on wishful thinking and selective memories.

“The mind does play a role in illness,” he said. “But the idea that death is something that an individual patient can control by sheer force of will — just from looking at the data, this doesn’t appear to be so.”

Some doctors and nurses who work with gravely ill people are not convinced by the findings, arguing that the statistics do not tell the human side of the story.

Young and statistician Erinn Hade looked at Ohio death certificates for people who died of cancer from 1989 to 2000 and analyzed how many deaths occurred before and after three dates — Christmas, Thanksgiving and the person’s birthday.

'There was no dip'“If there was an effect, you’d see a dip before ... and an increase after,” Young said. But there was no dip, and no significant difference in the proportion of cancer patients dying before an event and those dying after.

The study was published in Wednesday’s Journal of the American Medical Association.

“I can’t believe they’d put this out right before Christmas,” said Dr. Daniel Loiterstein, a specialist in geriatric psychiatry at Rush University Medical Center in Chicago. “It’s like walking around and telling people there’s no Santa Claus.”

Loiterstein said the study does not take into account individual situations and fails to consider that events other than holidays might be more important for some dying patients.

“We have all had the experience of watching a patient wanting to be there for their daughter’s wedding day, a grandfather wanting to be there for the grandson’s bar mitzvah or a Communion,” Loiterstein said. “I don’t think we should ever discount the power of hope and the power of these emotional events to move patients.”

Other studies supporting the phenomenon include University of California at San Diego sociologist David Phillips’ research showing declines in death rates among Jewish men before Passover and among elderly Chinese women before the Harvest Moon Festival.

'When it’s their time, it’s their time'Young said it is possible that the numbers of people wanting to hang on were evenly balanced by those wishing to die before the event. But he doubts it.

“I just don’t think that a patient wishes to die ‘early’ and ‘to get it over with’ — particularly when we seem to put an emphasis on a courageous ‘fight’ against cancer,” he said.

Nancy Whetstone, a Columbus, Ohio, executive whose parents both died in 1999 between Thanksgiving and Christmas, said she agrees with the findings.

“I don’t think people hang on for a specific event; I think when it’s their time, it’s their time,” she said.

But Pauline King, a nurse at Ohio State’s Arthur G. James Cancer Hospital, recalled an ailing, single mother of four who had advanced breast cancer and managed to fulfill her wish to survive until after her daughter’s 18th birthday.

“Maybe it happens less than we think, but when it happens, it sticks in your mind,” King said. “These people have a raison d’être.”